Method of molding hollow objects from cement.



, J. M. BOYLE. l METHOD OP MOLDINO HOLLOW OBJEOTS PROM O EMENOT.

APPLICATION FILBP JAN.' 23, 1907.

Milli 'N lWITNESSES.

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v PATNTEO JUNE 25. 190s UNITED STATES PATENT OFFICE.

JAMES M. BOYLE, OF NEW YORK, N. Y., ASSIGNOR TO MONOLITHIC DUCT (OMPANY, A CORPORATION OF NEW YORK.

I Specication of Letters Patent.

Patented June 25, 190'?4 Application filed January 23.1907. Serial No.353.692A

Leners Patent No. seloger, granted to me Se tember 4, 1906-.

. he. invention consist-s in the method of making a hollow object, which consistsv in preparing a bed of plastic material capable of ardening, forming a matrix in said bed,

lplacing in said matrix a iiexible fluid distended core., covering said core with further plastic material, andl finally removing said distendinv tluid from said core after said material has hardened su'tliciently to retain its shape: also in embedding in said plastic material a gas distended ilexible tube, substituting for said gas, liquid under pressure, and finally removing` said li uid from said tube after said material has ardened Suthciently to retain its shape: also in the specific modes of practicing my said method more particularly setft'orth in the claims.

In the. accompanying drawings-Figure .l is a longitudinal section of a conduit mold, showing -the gas distended tubular core in place and embedded in the plastic material.

`ig. 2 is a cross section of the mold, Wit-h a bed of plastic material therein, havin on its upper surface a matrix to receive t ie distended core. Fig. 3 is a cross section on the line a: of Fig. l. Fig. l is a longitudinal section similar to Fig. l, showin@ the distending gas replaced by liquid. Eig. 5 is a: section showing the construction of the plu which closes one end of the tubular core and through which air and liquid are admitted.

Similar numbers of reference indicate like parts.

1 is a distei'isible. tube of suitable dimensions to serre when distended as a core for the plastic material which forms the hollowv object to be molded. Any impervious ilexible material may be used for said core such as rubber covered fabric. One end 2 ot the z tubular core 1 is placed a metal ring 7.

struction. In the other end of the core is inserted an expansible plug, Fig. 51 constructed as' follows z Uponthe threaded pipe 4, are, two beveled disks 5 of metal. Oircumerentially inclosing said disks is a sleeve 6 of rubber, or other elastic material. On the exterior of' the The plug being inserted in the end of core 1, the outer disk 5 is turned in any suitable Way to cause compression of the rubber sleeve 6, and hence expansion thereof radially, to compress the Wall of said core between said sleeve and the'outer ring 7.

Extending through the threaded pipe 4 is a pipe R, the inner end ot which vvithii'i the core l is preferably bent radially, as shown in Fig.y 5. The outer end-of said pipe connects vwith any suitable form of gas relief valve,v indicated at 9. lIn said ipe is a valve l0. The valve 9 is mounte on a coupling 11, which connects pipe 4 with a two-Way valve l2, operated by the handle 13. When valve 12 is'adjusted in one'position, as for example, the position shownin Fig. 1, it establishes connection from the pipe 14 leading to any source Act-gas, preferably air, under pressure, t-o the interior of tubular corel. When valve- 12 is adjusted in another position, as for example, the posit-ion shown m Fig. 4, it establishes connection from the pipe l5 leading to any source B ot liquid, preferablyvvater, under pressure, to the interior of tubular core. 1. On coupling 11 is an escape pipe 16, having valve 17. 'Vhen the valve 12 1s ad justed in the position midway between those shown in Figs. 1 and 4, both pipes 14 and 15 may be closed.

In carrying my invention into practical effect, I preferably first place in a suitable mold, such for example, as the trough or box 18, a bed 19 ot the chosen plastic material. This term includes cement or concrete or any plastic mass, suitable to the object in view, which hardens on setting. While said bed is still plastic I form on its upperl surface by anv suitable means, a matrix, groove or channel 20; the depth of which may be' `equal to the. semidiameter ofthe tubular core l, when distended. This tubular core I diste-nd by gas, the plugs before described being inserted 1n the ends, and the valve 12 being placed as in Fig. 1, to establish` connection with the source of gas under pressure. I may effect IOO this distention before laying the corein the roove 20 or afterward. istended tube substantia I then introduce further about fill the mold as s valve 12 is then shifte under pressure.

sure of said li ui of the gas in t places said sure in the -core i tic material is set and har to retain its shape, after which t core, covering said core with further plastic material and finally removing said distending iuid from said core after said material has hardened sufficiently to retain Vits shape. 2. The method of making a hollow object which consists in embeddingl in a plastic ma terial capable Aof hardening, a gas distendedl flexible core, then substituting for said gas, llquid under pressure, and finally removing sald liquid from said core after said material has hardened sufficiently to retain its shape.

3. The method of making a hollow object which consists n preparing a bed of plastic material capable of hardening, placing a gas distended flexible core thereon, covering said core with further Iplastic material, substitut- 1s turned to close both valve 17V is opened to a cape. The core l being may then be drawn out o duit, the plug at .either for the purpose.

The principal advanta s as the distendin the cole, is the avoidance of lea thefabric of the tube. ample, is used, it will pores in the fabric, whi impervious to Water. found that the liquid fill smoother surface on the ipes-lfl, 15, and the ow the liquid to esno longer distended fthe completed conend being removed ge of substitu medium of age through Where air, for ex penetrate very fineV ch are substantially It is furthermore ed core produces a interior of the conliquid for ga d of making a hollow object preparing a bed of plastic oflhardenin guiding t e core, p aciiexible fluid distended 1. The metho which consists i material capable said bed,"a matrix for ing in said matrix a ing for said gas, 1

nally removing said liquid from said core after said material has hardened sufficiently to retain its shape.

4. AThe method of making a conduit which consists in preparing a bed of plastic material capable of hardening, forming in said bed a groove or channel, placing in said groove or channel a substantially close fitting gas distended flexible tubular core, covering said quid under pressure, and

core with further plastic material, substitut ing for said distending gas, a liquid under ressure, and finally removing said liquid om said core after said material has hardened sufiiciently to retain its shape.

In testimony whereof I have aiiixed my signature in presence of twovwitnesses.

JAMES M. BOYLE.

Witnesses: JEANNIE HAsTIE, GERTRUDE T. PORTER. 

